Question

我无法将值存储在共享偏好中。只要活动关闭，就会保存无值。再次启动活动时，用于存储和获取数据的ID具有空值。继承人是我的代码。我没有附上布局，因为它们没有意义。因为我是android的新手。可能会有一些简单的事情我不知道。请帮助

    public class enter_db extends AppCompatActivity
    {
    String field;
    EditText usrtext,idtxt,bananatxt,coconuttxt,timbertxt,bambootxt,goldtxt,garage1txt,garage2txt,garage3txt,garage4txt,garage5txt;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.db_entry);
    usrtext=(EditText)findViewById(R.id.username);
    idtxt=(EditText)findViewById(R.id.UserID);
    bananatxt=(EditText)findViewById(R.id.banana_count);
    coconuttxt=(EditText)findViewById(R.id.coconut_count);
    bambootxt=(EditText)findViewById(R.id.banana_count);
    timbertxt=(EditText)findViewById(R.id.Timber_count);
    goldtxt=(EditText)findViewById(R.id.gold_count);
    garage1txt=(EditText)findViewById(R.id.garage_1);
    garage2txt=(EditText)findViewById(R.id.garage_2);
    garage3txt=(EditText)findViewById(R.id.garage_3);
    garage4txt=(EditText)findViewById(R.id.garage_4);
    garage5txt=(EditText)findViewById(R.id.garage_5);
    SharedPreferences pref=getApplicationContext().getSharedPreferences("MyPref", MODE_PRIVATE);
    final SharedPreferences.Editor editor = pref.edit();
    if(pref.getString("Username",null)!="")
    {
    field=pref.getString("Username",null);
        usrtext.setHint("Username"+field);
    }
    if(pref.getString("UserID",null)!=null)
    {
        field=pref.getString("UserID",null);
        idtxt.setHint("UserID: "+field);
    }
    if(pref.getString("Banana",null)!=null)
    {
        field=pref.getString("Banana",null);
        bananatxt.setHint("Banana: "+field);
    }
    if(pref.getString("Coconut",null)!=null)
    {
        field=pref.getString("Coconut",null);
        coconuttxt.setHint("Cococnut: "+field);
    }
    if(pref.getString("Timber",null)!=null)
    {
        field=pref.getString("Timber",null);
        timbertxt.setHint("Timber: "+field);
    }
    if(pref.getString("Bamboo",null)!=null)
    {
        field=pref.getString("Bamboo",null);
        bambootxt.setHint("Bamboo"+field);
    }
    if(pref.getString("Gold",null)!=null)
    {
        field=pref.getString("Gold",null);
        goldtxt.setHint("Gold: "+field);
    }
    if(pref.getString("Garage1",null)!=null)
    {
        field=pref.getString("Garage1",null);
        garage1txt.setHint("Garage1 :"+field);
    }
    if(pref.getString("Garage2",null)!=null)
    {
        field=pref.getString("Garage2",null);
        garage2txt.setHint("Garage2 :"+field);
    }
    if(pref.getString("Garage3",null)!=null)
    {
        field=pref.getString("Garage3",null);
        garage3txt.setHint("Garage3 :"+field);
    }
    if(pref.getString("Garage4",null)!=null)
    {
        field=pref.getString("Garage4",null);
        garage4txt.setHint("Garage4 :"+field);
    }
    if(pref.getString("Garage5",null)!=null)
    {
        field=pref.getString("Garage5",null);
        garage5txt.setHint("Garage5 :"+field);
    }

    editor.putString("Username",usrtext.getText().toString());
    editor.putString("UserID",idtxt.getText().toString());
    editor.putString("Banana",bananatxt.getText().toString());
    editor.putString("Coconut",coconuttxt.getText().toString());
    editor.putString("Timber",timbertxt.getText().toString());
    editor.putString("Bamboo",bambootxt.getText().toString());
    editor.putString("Gold",goldtxt.getText().toString());
    editor.putString("Garage1",garage1txt.getText().toString());
    editor.putString("Garage2",garage2txt.getText().toString());
    editor.putString("Garage3",garage3txt.getText().toString());
    editor.putString("Garage4",garage4txt.getText().toString());
    editor.putString("Garage5",garage5txt.getText().toString());
    ImageButton ok=(ImageButton)findViewById(R.id.ok);
    ok.setOnClickListener(new View.OnClickListener() {
        // Start new list activity
        public void onClick(View v)
        {
            editor.apply();
            Intent i=new Intent(getApplicationContext(),Garage.class);
            startActivity(i);
        }
    });
}

}

Answer 1

你错过了apply（）/ commit（）来保存chanegs。

index.php

apply（）更快，异步，而commit（）是同步的。

Answer 2

 editor.putString("Garage5",garage5txt.getText().toString());
 editor.commit();

Answer 3

Save value in shared preferences:

SharedPreferences settings =getSharedPreferences("AppName", 0);
            SharedPreferences.Editor editor = settings.edit();
            editor.putString(key, value);
    editor. putBoolean(key, value);
            editor.commit();

get value from shared preferences:

 SharedPreferences settings = getSharedPreferences("AppName", 0);
            String value=settings.getString(key, ""); 
    boolean value=settings.getBoolean(key,false);

Answer 4

与上面的代码一样，您不会在按钮点击时保存共享首选项中编辑文本的值，请尝试这种方式

ok.setOnClickListener(new View.OnClickListener() {  // Start new list activity  public void onClick(View v)  {  editor.putString("Username",usrtext.getText().toString());  editor.putString("UserID",idtxt.getText().toString());  editor.putString("Banana",bananatxt.getText().toString());  editor.putString("Coconut",coconuttxt.getText().toString());  editor.putString("Timber",timbertxt.getText().toString());  editor.putString("Bamboo",bambootxt.getText().toString());  editor.putString("Gold",goldtxt.getText().toString());  editor.putString("Garage1",garage1txt.getText().toString());  editor.putString("Garage2",garage2txt.getText().toString());  editor.putString("Garage3",garage3txt.getText().toString());  editor.putString("Garage4",garage4txt.getText().toString());  editor.putString("Garage5",garage5txt.getText().toString());   editor.apply();  Intent i=new Intent(getApplicationContext(),Garage.class);  startActivity(i);  } });

SharedPrefereces无法保存值

4 个答案: